Security document

• US 20050181160A1
• Filed: 04/16/2003
• Published: 08/18/2005
• Est. Priority Date: 04/19/2002
• Status: Active Grant

• Current Assignee: Giesecke & Devrient GmbH
• Original Assignee: Giesecke & Devrient GmbH
• Inventors: Schneider, Walter
• Granted Patent: US 7,449,212 B2
• Time in Patent Office: Days
• US Class Current: 428/36.400
• CPC Class Codes: B42D 2033/16 Magnetic or magnetisable material
• CPC Class Codes: B42D 2033/20 Coloured material; Pigments or inks
• CPC Class Codes: B42D 25/29 Securities; Bank notes
• CPC Class Codes: B42D 25/369 Magnetised or magnetisable materials
• CPC Class Codes: B42D 25/378 Special inks
• CPC Class Codes: B42D 25/387 absorbing or reflecting ultraviolet light
• CPC Class Codes: G02B 26/026 based on the rotation of particles under the influence of an external field, e.g. gyricons, twisting ball displays based on orientable dipolar particles G02F1/172; based on electrophoresis G02F1/167
• CPC Class Codes: Y10T 428/1372 Randomly noninterengaged or randomly contacting fibers, filaments, particles, or flakes

Abstract

A security document with a security element, wherein the security element includes at least partly a material that is optically changeable by an electric or magnetic field. In addition, a corresponding method for producing such a security document and a test method for testing such a security document are described.

Claims

1. A security document (1) with a security element (2, 3) comprising at least partly of a material (M) that is optically changeable by an electric field (E) or magnetic field, characterized in that the security document is equipped for the purpose of testing thereof to produce an optical change of the material (M) by bringing the security document into an external electric or magnetic field.

2. A security document according to claim 1, characterized in that the optically changeable material (M) includes a plurality of particles (8, 9) that are changeable in at least one of their position or alignment by means of an electric field (E) or magnetic field.

3. A security document according to claim 1, characterized in that the security element (3) includes information (3) applied to the security document (1) and at least partly of the optically changeable material (M).

4. A security document according to claim 1, characterized in that the security element (2) includes a security layer (2) comprising at least partly of the optically changeable material (M).

5. A security document according to claim 4, characterized in that the security layer has a structure.

6. A security document according to claim 3, characterized in that at least one of the security layer (2) or the optically changeable information (3) has different colors in dependence on an electric field (E) or magnetic field from a certain viewing side.

7. A security document according to claim 3, characterized in that at least one of the security layer (2) or the optically changeable information (3) is transparent or opaque in dependence on an electric field (E).

8. A security document according to claim 4, characterized in that information to be protected is applied to a security layer.

9. A security document according to claim 4, characterized in that a security layer (2) covers information (10) applied to the security document (1).

10. A security document according to claim 1, characterized in that the material is adapted to be brought by irradiation of light into a state in which it is optically changeable by an electric field.

11. A security document according to claim 2, characterized in that the particles of optically changeable material are embedded in a substance that produces an electric field upon irradiation of light.

12. A security document according to claim 1, characterized by a layer that produces an electric field upon irradiation of light.

13. A security document according to claim 1, characterized in that the optically changeable material is soluble by at least one of organic media or water.

20. A test method for testing a security document according to claim 1, characterized in that the security document (1) is exposed for testing purposes to an external electric field (E) or magnetic field.

21. A test method according to claim 20, characterized in that the electric or magnetic field is structured.

14. A method for producing a security document (1) with a security element (2, 3), the security element (2, 3) being produced using a material (M) that is optically changeable by an electric field (E) or magnetic field, the optically changeable material (M) including a plurality of particles (8, 9) that are changeable in at least one of their position or alignment by means of an electric field (E) or magnetic field, the optically changeable material (M) being produced by enclosing the particles (8, 9) in microcapsules (7) and incorporating them in a binder (6), characterized in that for activating the optically changeable material (M) the microcapsules (7) are brought by a swelling agent into a swollen state in which the particles (8, 9) are supported movably in the microcapsules (7), the optically changeable material (M) being applied to the security document (1) in a nonactivated state.

15. A method according to claim 14, characterized in that for producing the optically changeable material (M) the particles (8, 9) are incorporated in an ink or toner as pigments.

16. A method according to claim 14, characterized in that the security element (3) applied to the security document (1) using the optically changeable material (M) is information (3).

17. A method according to claim 14, characterized in that the security element (2) applied to the security document (1) using the optically changeable material (M) is a security layer (2).

18. A method according to claim 14, characterized in that at least one of the security layer or information is produced on the security document by means of a nonactivated optically changeable material, and the security document is treated with a swelling agent to activate the optically changeable material.

19. A method according to claim 14, characterized in that at least one of the security layer or information is produced on the security document by means of a material including the nonactivated optically changeable material and microcapsules containing the swelling agent required for activation, and activation of the optically changeable material on the document is effected by destroying the microcapsules with the swelling agent.